JPH05208438A - Hose and its manufacture - Google Patents

Abstract

PURPOSE:To provide strong and easily flexible hose, in which the interlaminar bonding force is strong and no separation between bonding areas occurs even after a large number of flexing. CONSTITUTION:In order to produce the hose concerned, co-extrusion is carried out under the condition that polyolefin-based resin mixed with crosslinker is extruded inside and low-molecular-weight polyolefin is extruded outside, and, after that, the polyolefin-based resin is cooled down during its crosslinking process so as to produce inside portion 10 consisting of the polyolefin-based crosslinked resin layer 11 and the low-molecular-weight polyolefin layer 12. After covering rubber such as sponge rubber or the like is extruded onto the outside of the low-molecular-weight polyolefin layer 12 the resultant assembly is vulcanized at the high temperature exceeding 180 deg.C and under normal pressure so as to produce covering rubber layer 20 and, at the same time, melt the low- molecular-weight polyolefin layer 12 in order to bond the polyolefin-based crosslinked resin layer 11 and the covering rubber layer 20 with each other through the low-molecular-weight polyolefin layer 12 for manufacturing the hose concerned.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strong and flexible hose in which multiple layers of different rubbers or rubber-like elastic materials are superposed.

[0002]

2. Description of the Related Art As a hose that is already strong and easy to bend,
Different rubber or rubber-like elastic materials are layered on top of each other and wires / fibers are embedded as a reinforcing material (blade)
However, the treatment and application of adhesive is a manufacturer's original know-how, and depending on its formulation, the adhesive surface can be easily peeled off, and in order to obtain the desired physical properties, low temperature (150 ~ There is a problem that it is necessary to vulcanize under high pressure (pressurized steam) at 180 ° C for a long time.

[0003]

The problem to be solved is that, in a conventional strong and flexible hose in which multiple layers of different rubbers or rubber-like elastic materials are superposed, the adhesive surface is easily peeled off and a desired hose is desired. To obtain the physical properties of
It is necessary to vulcanize for a long time under high pressure (pressurized steam) at 0 to 180 ° C).

[0004]

The method for producing a hose according to the present invention comprises: after coextruding a cross-linking agent-containing polyolefin resin inside and a low molecular weight polyolefin outside,
A step of manufacturing the inner portion 10 composed of the polyolefin crosslinked resin layer 11 and the low molecular weight polyolefin layer 12 by cooling while crosslinking the polyolefin resin, and a cover rubber such as sponge rubber is extruded on the outside of the low molecular weight polyolefin layer 12. At the same time, the cover rubber layer 20 is formed by vulcanization at a high temperature exceeding 180 ° C. under normal pressure, the low molecular weight polyolefin layer 12 is melted, and the low molecular weight polyolefin layer 12 is used to form the polyolefin cross-linked resin layer 11. The step of bonding the cover rubber layer 20 together.

The hose according to the present invention comprises a polyolefin-based crosslinked resin layer 11 and a low molecular weight polyolefin layer 12
And a cover rubber 20.

[0006]

EXAMPLES Examples will be described with reference to the drawings. As shown in FIGS. 1 to 3, PE / PP or other polyolefin resin mixed with a crosslinking agent by a resin co-extruder 50 is placed inside and PE or other low molecular weight polyolefin. Is co-extruded on the outside, and then the polyolefin-based resin is cooled 52 while being cross-linked 51 to manufacture the inner portion 10 including the polyolefin-based cross-linked resin layer 11 and the low molecular weight polyolefin layer 12. Next, a cover rubber made of olefin rubber such as EPDM or a sponge rubber thereof is extruded to the outside of the low molecular weight polyolefin layer 12 by a rubber extruder 60, and the rubber is heated in a vulcanizing furnace 70 under high temperature and normal pressure exceeding 180 ° C. Is vulcanized to form the cover rubber layer 20, the low molecular weight polyolefin layer 12 is melted, and the polyolefin-based crosslinked resin layer 11 and the cover rubber layer 20 are bonded via the low molecular weight polyolefin layer 12. In addition,
As shown in FIG. 3, the low molecular weight polyolefin layer 12 can be made thick and the reinforcing fiber yarn 13 can be embedded (blade) therein.

Explaining the operation, the above-mentioned manufacturing method enables high-speed vulcanization of the cover rubber at high temperature and normal pressure.
The obtained hose comprises a polyolefin-based crosslinked resin layer 11 and a cover rubber layer 2 with a low-molecular-weight polyolefin layer 12 interposed therebetween.
Since they are bonded to each other, the bonding strength is strong, and the bonding surface does not peel off even when bending many times. Further, in the braided material, the resin is melted and enters the reinforcing fiber thread 13 during vulcanization and physical adhesion is performed, so that the adhesive force is stable regardless of humidity, for example.

[0008]

Since the present invention is constructed as described above,
The obtained hose, whether braided or not, has a strong adhesive force between the olefin-based crosslinked resin layer 11 and the cover rubber layer 20, and the adhesive surface is not peeled off even when bent many times.

[Brief description of drawings]

FIG. 1 is a manufacturing process diagram showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a non-bladed hose obtained by practicing the present invention.

FIG. 3 is a cross-sectional view of a braided hose obtained by implementing the present invention.

[Explanation of symbols]

 10 Inner part 11 Polyolefin cross-linked resin layer 12 Low molecular weight polyolefin layer 13 Reinforcing fiber yarn 20 Cover rubber layer 50 Co-extruder for resin 51 Cross-linking 52 Cooling 60 Extruder for rubber 70 Vulcanizing furnace for rubber

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display area F16L 11/04 7123-3J // B29K 21:00 23:00 105: 04 B29L 9:00 4F 23 : 00 4F

Claims (2)

[Claims] 1. A polyolefin-based crosslinked resin layer (11) and a low-molecular-weight polyolefin layer are co-extruded with a crosslinking-agent-containing polyolefin resin inside and a low-molecular-weight polyolefin outside, and then cooled while crosslinking the polyolefin-based resin. A step of producing an inner part (10) consisting of (12), a cover rubber such as sponge rubber is extruded on the outside of the low molecular weight polyolefin layer (12), and then vulcanized at a temperature higher than 180 ° C. and a normal pressure, The cover rubber layer (20) is formed, and the low molecular weight polyolefin layer (1
2) is melted and the low molecular weight polyolefin layer (1
A hose manufacturing method comprising a step of adhering a polyolefin-based crosslinked resin layer (11) and a cover rubber layer (20) via 2). 2. A hose composed of a crosslinked polyolefin resin layer (11), a low molecular weight polyolefin layer (12) and a cover rubber layer (20).